Vision Correction About 75% of the U.S. population uses some type of vision correction

(such as glasses or contact lenses).

a. If someone is randomly selected, what is the probability that he or she does not use vision correction?

b. If four different people are randomly selected, what is the probability that they all use vision correction?

c. Would it be unlikely to randomly select four people and find that they all use vision correction?

Why or why not?